Electrical air condenser



Dec. 18, 1923. 1,478,347

R. c. LEWIS ELECTRICAL AIR CONDENSER Filed Jan. 51. 1921 2 Sheets-Sheet1 Dec. 1-8, 1923.

R. C. LEWIS ELECTRICAL AIR CONDENSER Filed Jan. 31. 1921 2 Sheets-Sheet2 Patented Dec. 18, 1923.

UNITED STATES PATENT OFFICE.

RALPH C. LEWIS, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO COTO-COILCOMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

ELECTRICAL AIB CONDENSER.

Application filed January 31, 1921. Serial No. 441,115.

To all whom it may concern.

Be it known that I, RALPH C. LEWIS, a citizen of the United States,residing at Providence, in the county of Providence,

State of Rhode Island, have invented certain new and useful Improvementsin Electrical Air Condensers, of which the follow-- ing is aspecification.

My invention relates to electrical air-condensers of the variable typeand consists in improvements in the mechanical design and constructionof the same.

The principal object of the improvement is to simplify the structure andcheapen the cost of manufacture of the device while rendering it highlyefiicient for the purpose desi ed.

Further objects of the improvement are set forth in the followingspecification which describes a referred embodiment of the invention asilustrated by the accompanying drawings, in which likereferencecharacters designate like parts. In the drawings:

Fig. "tie a plan view of my improved air-condenser;

Fig. 2, a vertical sectional elevation of the same taken on the line 2-2of Fig. 1; and

Fig. 3, a detail plan view showing the arrangement of the condenserplates.

My improved air-condenser is of a wellknown type as used with radioapparatus and comprises in general a series of spaced apart platesarranged in fixed relation, with a second set of movable plates adaptedto be swung between the fixed lates, in alternate relation thereto, andwit a variable degree of overlap to regulate the capacitive effect. Asbefore stated, my invention relates particularly to the mechanicalstructure of the apparatus and consists in an improved mounting for theplates and a simplified method of assembling them thereon.

Referring to the drawings, the mounting for the condenser-platesconsists essentially of a metal, spider-like member 2 comprising a hubor bearing 3 with arms 4.- radiating from. an axis in offset relation tothe center of the hub. At the outer ends of the arms 4 are rin -likebosses 5 with ribs 6 extending longitudinally of the arms between thebosses and the hub 3 to reinforce the structure, see Figs. 2 and 3. Onthe top of the bosses 5 are cylindrical hubs. 7 which are shouldered at8 to adapt them to fit into the ends of the bores 9 of the bosses.Similar hubs 10 are fitted to the bottom of the bosses 5 and with theupper hubs 7 form a continuation or extension thereof. The hubs 7 and 10are constructed of hard rubher, vulcanite, bakelite or similardielectric material and are provided with axial bores for receiving rods14 which hold the fixed condenser plates 15 on the spider or mounting 2.The hubs 7 and 10 are preferably counterbored at 16 and with the bores 9of the bosses 5 provide air spaces surrounding the rods 14 to insulatethem from the metal of the spider 2. At the upper ends of the hubs 7 arecounterbores 17 adapted to re ceive nuts 18 screwed onto the threadedends of the rods 14. The rods 14 project down through the lower hubs 10to adapt them to be inserted through holes in the fixed condenser-plates15 which are arranged in superimposed relation and held spaced-apart bya series of Washers or collars 19.

As shown in Fig. 3, the fixed plates 15 are of substantiallysemicircular shape in outline and the three rods 14 pass through holesspaced equidistantly around their curved edges. Referring to Fig. 2, Ihave here shown twelve fixed plates but the number is arbitrary and maybe varied at will. The plates 15 are held on the rods 14 by nuts 20 attheir lower ends, which, with the upper nuts 18 also serve to clamp thehubs 7 and 10 in place a ainst the bosses 5. The upper threaded en s ofthe rods 14 extend beyond the nuts 18 and are adapted to project throughsuitable holes in a circular plate 21 which is constructed of hardrubher or other suitable dielectric material and constitutes the coveror support for the condensers. In some cases the plate 21 forms the topor cover of a circular casing enclosing the complete apparatus and. nuts22 are screwed onto the upper ends of the rods 14.- against washers 23to bind the hubs 7 against the under side of the cover.

Referring to Fig. 3, the movable plates 25 are of substantially the samecontour as p the fixed plates 15 except that they are cut away orrounded off at one end and are provided with'ofi'set tabs 26 by whichthey are attached to a rotatable spindle 27, see Fig. 2, by means ofwhich they may be swung to different ositions in relation to the fixedplates 15. he spindle 27 is mounted to turn in hearings in the huh 3 endcerries a knurled knob 28 at its upper end for operating it. As shown in2, the beerings for the spindle 27, are mounted in s 5 bushing orthimhle 30 adopted to be quickly and easily assembled in the hub 3 ofthe spider 2 and also providingfor convenient adjustment of the spindlein the direction of its axis, WheYehy to allow for properly set ting themovable plates equitlistsntly hetween the fixed plates 15.,

The thimhle is screw-threaded on its exterior and fits loosely Withinenlarged bore 31 in the hub Screwed onto its i5 opposite ends aresuitable nuts 33 which are tightened against the top bottom faces of thehub 3 to secure the bushing 30 fixedly therewith. By loosening; one outand tightening the other the imhle El so in may be soljustecl in eithet:direction oxiisflly oi the huh- 3 whereby to sccmstely locste thespindle 27 with its plates in proper eclsxtion with the fiztetl platesThe thinihle 30 is ptovicletl with hose 5ft" "posses with 1 throughwhich spindle clearance srouho i sides, site at its top and ho -tom agecountethores 35 36 selected to "receive l 3? The rings 3'5 formed "withx71 l tom sub of v. a a n .1 KO 11 W donations o. oo. o

meht oil the swinging plates 25 under the turning action of the spinolleQ7 (to the top of the plate or cover 21 are two binding-posts 54; and 55of usual m 1rengement see Fig. l the post 5% being electricallyconnected with the fiXeCl plstes 15 by a Wire 56 leading to one of thelOiZlS 14:; While the-other post 55 2t Wire 5'? leech ing to the spimlle27' which carries the movethle plates 25 The Wire 57 is ptetemloly list1" ribbon-like sncl is coiletl shout the spindle 27 in s spiral so thatthe latte? may he rotzttec. freely Without interference.

My improved condenser may he applied to use in the position shown in thetltswings with cylintlricsl casing enclosing its parts, 01 it may heiiito s vertical plate 01 hostel if clesiiretlt The olevice is connectedin citcuit with the radio eppei'stus by means of the two himlingmosts54; shot sncl hy tum ing; the lmoh the spindle Q? is rotated to swingthe movshle "plates 525 between the fixed lstes The dial it) is fiXQClon the spin le 27 in such goosition that Wh 1': its zero moth registerswith the point on the cover l the plates will he set with them 3 inparallel, spstcecl eels,- tioit "hi the opposite stifsight edges of thei q t hxeo Jlstes en the motes iii bet l swung MEG plates "fl Wl'leii -sthe open-st oi' spindle the movable coho .SGL QlEJtES "1 L meets. to olemote,

rangement whereby the bearing may be assembled as a unit with thespindle and then applied to the mounting or spider-member 2 and readilyadjusted to position to set the two series of condenser-plates incorrect relation with very little labor and practically no fitting.Another feature of the improvement consists in the method of connectingthe fixed plate supporting rods with the spider or mounting to providean extended airchamber or pocket surrounding the rods where they passthrough the hollow bosses on the arms, whereby to secure a minimumcapacitive effect between the metal rods and the metal mounting. It isalso brought to attention that while the complete device is particularlystaunch and rigid in structure its weight is reduced to the minimum andthe heavy, expensive composition plates and insulators have beeneliminated. Furthermore, such parts of insulating material as arenecessary are designed for strength, and constructed to minimize thedanger of cracking or splitting when assembled with the metaltastenings.

The above description and the accom anying drawings illustrate myimproved evice in its preferred form and slight variations in design andstructure of the parts of the ap paratus may be made without departingfrom the spirit or scope of the invention. Therefore, without limitingmyself to the exact embodiment of the invention as herein set forth, Iclaim:

ser comprising a single unitary mounting having a hearinghub withextending suhstantially radi ally therefrom, a series of fixedcondenserplates suspended from the ends of the arms in superimposedspaced-apart relation, a spindle journaled in a plura in the hub andprojectin therefrom, condenser ty of hearin s downward y a secend seriesof inovahle ates mounted in superimposed spaced-ape. t relation on theprojecting portion of, the spindle to adapt them; to he swung into.ocsition between the fixed plates. 3. An electrical air-condensercomprising single ill mpunting, isting in a ra sande perimposedspaced-apart relation, rods ex tendin through the plates and supportedsolely roin their upper ends in the arms of the spider, means to securesaid rods in the arms while insulating them therefrom, a spindlejournaled in a plurality of bearings in the hub of the spider androjecting therebelow, and a second series oPsuperimposed spaced-apartplates mounted on the spindle to adapt'them to be swung into positionbetween the fixed plates.

4. In a variable air-condenser, the combination of a unitary mountinghaving a bearin -hub with arms radiating therefrom, insu ating hubssupported at the ends of the arms, rods secured in the insulating hubson the arms and projecting therehelow without other support, a series ofsuperimposed spaced-apart condenser-plates held in sus pended relationby the rods below the mountingd, a spindle journaled in the bearing-huban projecting downwardly therefrom, and a second series of movablecondenser-plates secured in superimposed spaced-apart relation on thelower projecting portion of the spindle. I

5. In a variable air-condenser, the combination of a unitary mountingconsisting of a spider-member having a hub and arms radiating therefrom.with hollow bosses at their ends, insulatin hubs fitted to the ends ofthe, bosses on t e arms, rods inserted through bores in the hubs, aseries of fixed condenser-plates arranged in superimposed relation onthe rods, means for holding said plates inspaced relation, nuts on theends of the rods for securing the plates in position and fastening therods in the hubs, a spindle journaled in the hearing-hub and projectingdownwardly therefrom and a series at superimposed movable plates mountedin spaced-apart relation on the pro jecting portion of the spindle.

6. In a variable air-condenser, the combination of a mounting having ahub, a series st superimposed spaced-apart condenserplates supportedfrom the rneunting, a bearing-thimble adjustable axially of the hub, aspindle journaled in hearings in the hub to adapt it for axial.adjustment therewith, and a series or superimposed plates mountedin-spoced-apart relation on the spindle'to adapt them. to be swungaround into overlapping relation with the fixed plates.

7 In a variable air-condenser, the comhi nation a mounting having abearing-hub, fixed condenser plates attached to the mountingsuperimposed spaced-apart relation, a thilnhle extending axially of thehearinghuh, nuts on the ends of the thimble for ad usting it in the hub,a spindle journaled in hearings in the thimhle, and a series ofsuperimposed spaced-apart plates sarried y spindle te adapt them to bebet-ween fixed plates.

sti t,

8. ln a variable air-condenser, the combination of a mounting having abearing-hub, fixed condenser-plates supported from the mounting insuperimposed spaced-apart relation, a thimble adjustable axially of thebearing-hub, conical bearing-rings in the thimble, a spindle extendingaxially of the thirnble, bearing-cones on the spindle seated against thebearing-rings in the thimble, means to exert a resilient pressure toforce the cones and rings toward each other, and a series ofsuperimposed spaced-apart condenser-plates carried by the spindle.

9. In a variable air-condenser, the combination of a mounting having abearing-hub, fixed condenser-plates supported from the mounting insuperimposed spaced-apart relation, a thimble in the hub, means foradjusting the thimble axially of the hub, conical bearing-rings in thethimble, a spindle extending axially ot' the thimble, a fixedbearing-cone on the spindle adapted to seat against one of thebearing-rings, a second bearing-cone slidable on the spindle to seatagainst the other ring, a spring for pressing the slidable cone towardthe fixed cone, and a series of superimposed spaced-apartcondenser-plates carried by the spindle.

10. In a variable air-condenser, the combination of a mounting having abearing-hub and arms radiating therefrom with hollow bosses at theirends, insulating hubs fitted to said bosses, rods extending throughbores in said hubs, a series of superimposed condenser-plates mounted inspaced-apart relation on the rods, a cover-plate fastened to the upperends of the rods, bearings adjustable axially of the bearing-hub, aspindle journaled in said bearings and adjustable axially therewith, aseries of superimposed condenser-plates mounted in spaced-apart relationon the lower part of the spindle, a knob on the upper end of thespindle, and a dial rotatable with the spindle and provided withgraduations on its edge adapted to register with an index mark on thecoverplate.'

11. In a variable air-condenser, the combinat'ion of a mounting havinghollow bosses supported therefrom, insulating hubs mounted on the bossesand having counterbores forming extensions of the bores in the bosses toprovide extended air-chambers, rods held in smaller bores at the outerends of the hubs, a series of superimposed condenser-plates mounted onthe rods in spaced-apart relation, a spindle journaled in hearings inthe mounting, and a series of superimposed spaced-apart plates carriedby the spindle to adapt them to be swung between the fixed plates.

in testimony whereof I affix my signature.

RALPH' C, 155.

